Power tools, such as screwdrivers and wrenches, by way of example, typically include a spindle designed to support a tool element (e.g., a socket). The spindle (and, hence, the tool element) rotate when driven by a power source of the power tool. In many power tools, the spindle is free to rotate when not being driven by the power source. As such, these power tools do not allow a user to manually apply a load to the spindle of the power tool to, for instance, tighten or loosen a fastener above the capability of the power tool. While some power tools may include a lock for selectively preventing rotation of the spindle, such locks typically require manual engagement and disengagement by a user of the power tool.